CN103573443B - The method and system controlled for engine unburned hydrocarbon - Google Patents

Abstract

The application is related to the method and system controlled for engine unburned hydrocarbon.Method and system is provided, monitored while for the heat release rise with exhaust uneven based on cylinder, the hydrocarbon suction of detection engine.Bent axle accelerates data to be monitored under stable state and transition engine operating condition, and delivery temperature is evaluated under non-renewable situation.Engine speed and load are limited, and are sucked with reducing further hydrocarbon.

Description

The method and system controlled for engine unburned hydrocarbon

Background of invention/summary of the invention

Due to a variety of causes, engine can cause cylinder moment of torsion uneven.These reasons may include, for example, the spray blocked Soot accumulation in hole in nozzle, over-pressurization, fuel mass problem and cylinder.Engine control system can be configured, to solve Certainly cylinder moment of torsion is uneven, so as to improve engine performance.

Reduce a kind of unbalanced case method of cylinder by being shown in by Yamaoka etc. in US7,128,048.Wherein, Based on cylinder pressure peak timing from the deviation of predetermined timing range, differentiate that cylinder is uneven.Based on cylinder pressure peak Value timing is delayed by or shifted to an earlier date relative to predetermined scope in given cylinder, the adjustable conveying of engine controller To the amount of the internal EGR of impacted cylinder.This causes the combustibility of mixture in cylinder to be improved, also, engine speed It is appropriately adjusted.If deviation is sufficiently large, the compression-ignition mode of engine operating can be suppressed, to reduce engine performance Decline.

However, the disclosure herein person has realized that the potential problems of such method.As example, internal EGR is adjusted Amount can not reduce by hydrocarbon that cylinder is uneven caused by engine charge accumulation.For example, in some engine systems, certain A little engine cylinders can be easier to hydrocarbon accumulation, and this is due to the particular configuration of engine aspirating system.Herein, increase internal EGR amount can be unfavorable for discharging hydrocarbon from those cylinders.As another example, hydrocarbon can be accumulated and stepped at charger-air cooler Engine is forced into during accelerator pedal at charger-air cooler.The amount of increase internal EGR can reduce stepping on plus The power provided during fast device pedal is without increasing release of the hydrocarbon from charger-air cooler.If being left on engine charge Place, the then hydrocarbon accumulated can be propagated finally from impacted cylinder to remaining cylinder, further resulted in cylinder imbalance and accelerated Engine performance fails.

Therefore, in an example, some above mentioned problems can be by operating the method for engine to be addressed, methods described Including：Response indicates cylinder imbalance and engine exhaust heat release rise, limitation engine speed and the load of hydrocarbon oxidation, to subtract Hydrocarbon accumulation at few engine charge.By this way, hydrocarbon can in the accumulation of the one or more positions along engine charge Preferably solved.

In an example, engine may include the gas handling system of branch, and it is provided respectively to first and second groups of cylinders Air.Due to the particular configuration of gas handling system, air can flow to breeches joint from air throttle, then from the first outlet of breeches joint It flow to first group of cylinder and the first outlet from breeches joint flow to second group of cylinder.The longitudinal axis of the first outlet of breeches joint can be right Accurate the first cylinder arranged away from first group of end cylinder, and the longitudinal axis of the second outlet of breeches joint can be aligned away from second First cylinder of the end cylinder arrangement of group.As a result, first group of the first cylinder and second group of the first cylinder can be easier to hydrocarbon Accumulation.Based in steady state engine operating mode (for example, idling conditions) and/or transition engine operating condition (for example, being stepped on stepping on accelerator During plate) under the bent axle assessed accelerate difference, engine controller can determine that cylinder is uneven.In steady-state conditions and transient working condition Under, camshaft data can be evaluated in different windows, and window is at least become based on Mass Air Flow in each case Change.Due to higher background noise, controller can carry out important signal transacting to the camshaft data received under transient working condition, Key dithering including signal, with distinguish due to caused by hydrocarbon accumulation at engine charge cylinder it is uneven with transient working condition by Cylinder is uneven caused by air or fuel change (for example, due to misfire).In addition, do not regenerated in exhaust gas particulate filter Under situation, controller can be assessed on exhaust catalyst (such as, exhaust oxidation catalyst)（Across exhaust catalyst, across an exhaust catalyst）The exhaust temperature difference.

The cylinder detected during response exhaust heat release rise is uneven, and controller can determine that to exist and accumulate at engine charge Hydrocarbon oxidation.In particular, uncontrolled hydrocarbon accumulation can occur in each position along engine charge, including occur in bent axle Case, generation are in the vicinity of specific cylinder air inlet and generation in charger-air cooler or generation in the attached of charger-air cooler Closely.Response indicates that controller can limit engine speed and load, is accumulated with reducing further hydrocarbon at engine charge.Limit System may include fuel injection of the limitation to all engine cylinders --- including unbalanced cylinder ---.The degree of limitation can base It is to be detected in transient working condition or in a steady-state condition in cylinder imbalance.For example, what response was detected under transient working condition Cylinder is uneven and heat release rise, and limitation can be higher and faster, and this is due to high α and β error separates, and response is in the steady state The cylinder of detection is uneven and heat release is raised, and limitation can be lower and slower, and this is due to less α and β error separates, and it is required Relatively low Key dithering ratio.Controller can also improve engine temperature, to discharge the hydrocarbon of accumulation.Herein, the hydrocarbon of accumulation In check oxidation or evaporation increase to crankcase fill overfill tolerance.Further, controller is settable one or many Individual diagnostic code, illuminate indicator lamp and message in groups is set（cluster message）, to alert vehicle driver at air inlet Hydrocarbon accumulation is detected, so that vehicle is delivered to service center by vehicle driver before occurring the substantive performance degradation of engine.

By this way, difference is accelerated to differentiate that cylinder is uneven under stable state and transition engine operating condition by using bent axle It is associated with exhaust heat release rise with by making cylinder uneven, because cylinder is uneven caused by the hydrocarbon accumulation at engine charge Weigh and can preferably be differentiated, and with accumulating caused cylinder imbalance and due to other engines by other engine location hydrocarbon Cylinder uneven (for example, due to those cylinders imbalance caused by fuel injector change) is distinguished caused by operating mode.Pass through The instruction limitation engine speed and load of the hydrocarbon accumulation at engine charge is responded, by the hydrocarbon that accumulates in upper air current amount situation (such as stepping on accelerator pedal) flows into primary engine performance decline caused by engine and can be lowered.In addition, by limiting hydrocarbon Further accumulation at engine charge, can be failed by the uneven potentially caused secondary engine performance of lasting cylinder can It is lowered.

In another embodiment, the method for engine includes：It is higher than based on the exhaust temperature difference on exhaust catalyst Each bent axle during threshold value between the first cylinder and the second cylinder accelerates difference, indicates the hydrocarbon accumulation in the first cylinder；And response Yu Qi, is limited to the respective fuel injection of the first and second cylinders.

In another embodiment, bent axle accelerates difference to be commented when engine is in steady-state conditions in first window Estimate, and be evaluated when engine is in transient working condition in second, different window, the second window is based under transient working condition Mass Air Flow be dynamically adjusted.

In another embodiment, the exhaust temperature difference is evaluated in non-renewable steady-state conditions.

In another embodiment, each for accelerating in difference and the exhaust temperature difference based on bent axle carries out indicating to include using the One weight factor weighting bent axle accelerates difference and is vented the temperature difference, the first and second weights with second, different weight factor weighting The factor at least accelerates difference to be to be evaluated in transient working condition or in a steady-state condition based on bent axle.

In another embodiment, limitation includes：When engine is in steady-state conditions, with first, it is relatively large limit to The respective fuel injection of first and second cylinders, and when engine is in transient working condition, limited with second, small amount to first With the respective fuel injection of the second cylinder.

In another embodiment, method also includes reducing engine speed, to reduce engine crankcase foaming.

In another embodiment, the method for engine includes：Under the first engine steady state situation, based on steady Bent axle accelerates difference and exhaust heat release rise between the cylinder assessed under state situation in first window, indicates at engine charge HC accumulation；Under the second engine transition operating mode, based on bent axle between the cylinder assessed in a second window under transient working condition Accelerate difference and exhaust heat release rise, indicate the HC accumulation at engine charge；With under the first and second situations, response refers to Show, limit the fuel injection to all engine cylinders.

In another embodiment, first window is to be based on engine speed and moment of torsion in a steady-state condition, and in transition The second window is to be based on quality air flow rate under operating mode.

In another embodiment, first window is wider than the second window.

In another embodiment, method is additionally included between the cylinder under the first steady-state conditions in Key dithering first window bent Axle accelerates difference, and under the second transient working condition, bent axle accelerates difference between the cylinder in the window of Key dithering second.

In another embodiment, response indicates that limit includes to the fuel injection of all engine cylinders：If it is indicated that Received under engine steady state situation, fuel injection is limited with the first weight factor, and if it is indicated that in engine transition work Received under condition, fuel injection is limited with the second weight factor, the first weight factor is higher than the second weight factor.

In another embodiment, limitation fuel injection includes：Under the first steady-state conditions, with first, relatively large limitation To under the fuel injection of all engine cylinders, and the second transient working condition, limited with second, small amount to all engine cylinders Fuel injection.

In another embodiment, the method for engine includes：During first steps on accelerator pedal, based on Bent axle accelerates difference and exhaust heat release between the cylinder assessed in one window, indicates the HC accumulation at engine charge；Second During stepping on accelerator pedal, difference and exhaust heat release are accelerated based on bent axle between the cylinder assessed in second, different window, referred to Show the HC accumulation at engine charge；With during first and second step on accelerator pedal, response is indicated, is limited to all hairs The fuel injection of engine cylinder.

In another embodiment, first window is based on the quality for passing through engine during first steps on accelerator pedal The rate of change of air mass flow and Mass Air Flow, and wherein the second window are to be based on passing through during second steps on accelerator pedal Cross the Mass Air Flow of engine and the rate of change of Mass Air Flow.

In another embodiment, during first steps on accelerator pedal, the rate of change of Mass Air Flow is higher than Second step on accelerator pedal during Mass Air Flow rate of change.

It should be appreciated that there is provided outlined above to introduce in simplified form to the concept that is further described in detailed description Selection.It is not meant to be the key or substantive characteristics that determine claimed theme, it is desirable to which the scope of the theme of protection is by described detailed Claims after thin description are uniquely limited.In addition, claimed theme is not limited to solve above or in the disclosure Hold the implementation of any shortcoming described in any part.

Brief description

Fig. 1 shows the partial view of engine system.

Fig. 2 shows the instance constructs of engine system.

Fig. 3 show program schematic description, the program based on the cylinder monitored under transient working condition and steady-state conditions not Hydrocarbon accumulation at balance and exhaust heat release, detection engine charge.

Fig. 4 shows high level flow chart, and it is based on the cylinder imbalance monitored under transient working condition and steady-state conditions and row Gas heat release, differentiates the hydrocarbon accumulation at engine charge.

Fig. 5 shows high level flow chart, and it responds the instruction of the hydrocarbon accumulation at engine charge, mitigates the operation performed （action）.

It is described in detail

Method and system is described, it indicates to start based on the uneven correlation between exhaust heat release rise of cylinder The uneven accumulation of hydrocarbon at the select location of machine air inlet (such as Fig. 1-2 engine system).Start in transient working condition and stable state Under machine operating mode, the exhaust temperature difference (Fig. 3) on bent axle acceleration difference and the exhaust catalyst between single engine cylinder is assessed.Control Device processed can be configured, and to collect the data in different windows, perform different signal transacting and be in the steady state also based on data It is that discriminatively weighted data (Fig. 4) is collected under transient working condition.Based on the instruction of the hydrocarbon accumulation at engine charge, control Device can perform one or more alleviation steps (Fig. 5), including limit the fuel injection to all engine cylinders, to accelerate product The release of tired hydrocarbon, while further reducing the accumulation at air inlet.By this way, the choosing due to engine charge can be mitigated Determine the engine performance decline that hydrocarbon is accumulated and caused at region.

With reference to Fig. 1, explosive motor 10 includes multiple cylinders, and one of cylinder is shown in Fig. 1, passes through Motronic control maps Controller 12 is controlled.Engine 10 includes combustion chamber 30 and cylinder wall 32, and wherein piston 36 is located therein and is connected to bent axle 40.Display combustion chamber 30 is connected with inlet manifold 44 and exhaust manifold 48 by respective inlet valve 52 and exhaust valve 54.It is each Inlet valve and exhaust valve can be operated by inlet valve cam 51 and exhaust valve cam 53.Alternatively, one or more air inlets Door and exhaust valve can be operated by the valve coil and armature assembly of Electromechanical Control.The position of inlet valve cam 51 can be by entering Valve cam sensor 55 and determine.The position of exhaust valve cam 53 can be determined by exhaust valve cam sensor 57.

Display fuel injector 66 is arranged, and to direct injection of fuel into cylinder 30, this is by those skilled in the art Referred to as directly spray.Alternatively, fuel can be injected into air inlet, and this is referred to by those skilled in the art as intake port injection. Fuel injector 66 conveys the liquid fuel proportional to the pulsewidth of the signal FPW from controller 12.Fuel passes through fuel system System (not shown) --- including fuel tank, petrolift and fuel rail (not shown) --- is transported to fuel injector 66.Extremely Fuel injector 66 is supplied the operation electric current of the driver 68 from response controller 12.In addition, display inlet manifold 44 with Optional electronic throttle 62 --- the position of regulation choke block 64, to control the air mass flow of air plenum 46 --- even It is logical.Compressor 162 attracts air from air inlet 42, to supply pumping chamber 46.Exhaust revolves the turbine 164 for being connected to compressor 162 Turn.High pressure, two-stage fuel system can be used for producing higher fuel pressure in injector 66.Shown with reference to Fig. 2 engine system The instance constructs of the inlet manifold of engine 10.

Display Universal Exhaust Gas oxygen (UEGO) sensor 126 is connected to the exhaust manifold 48 of the upstream of emission control system 70.Can Selection of land, bifurcation exhaust gas oxygen sensor may replace UEGO sensor 126.

Emission control system 70 may include one or more exhaust catalysts and particulate filter.In an example, such as Described, emission control system 70 may include the particulate filter 73 in the downstream of exhaust oxidation catalyst 71.In other instances, discharge Control device 70 may include one in SCR catalyst, three-way catalyst, light-off catalyst, oxidation catalyst and particulate filter It is individual or multiple.One or more temperature sensors may connect to emission control system 70, for assessing exhaust heat release.For example, the One temperature sensor 75 is attached to the upstream of emission control system 70, specifically, the upstream of exhaust oxidation catalyst 71, and the Two temperature sensors 77 are connected to the downstream of emission control system 70, specifically, the downstream of particulate filter 73.In addition, the 3rd Temperature sensor 76 is attached to exhaust oxidation catalyst 71B downstream, is commented with providing being vented heat release on oxidation catalyst Estimate.Similarly, one or more exhausts are empty-right than sensor (for example, UEGO, the EGO or HEGO lambda sensor) row of being attached to The upstream and downstream of control device is put, including the upstream and downstream of oxidation catalyst 71 and the upstream of particulate filter 73 are with Trip.

As elaborated herein, it is inhaled into hydrocarbon under the situation of engine, hydrocarbon accumulation can be along engine charge Occur and occur at engine exhaust, such as occur the area in particulate filter 73 and the upstream of adjacent oxidation catalyst 71 Domain.Oxidation of the hydrocarbon of accumulation at engine exhaust is exothermic reaction, and it discharges a large amount of abilities in emission control system.Especially Ground, under the situation that particulate filter is not reproduced, the oxidation of the hydrocarbon of accumulation causes big calorimetric to be released in oxidation catalyst 71 Downstream.Excessive heat can cause the performance degradation of emission control system 70.By assessing oxidation catalyst under non-renewable situation On the temperature difference, can detect heat release rise.By making heat release rise and adjoint cylinder uneven associated, hydrocarbon suction is can detect, Also, engine performance decline can be taken to alleviate step.

Controller 12 is as normal miniature Computer display in Fig. 1, and it includes：Microprocessor unit 102, input/output Port 104, read-only storage 106, random access memory 108, keep-alive memory 110 and conventional data bus.Except before Outside those signals discussed, display controller 12 also receives the various signals from the sensor being connected with engine 10, bag Include：ECT (ECT) from the temperature sensor 112 for being connected to cooling cover 114；Accelerator is connected to step on The position sensor 134 of plate 130, for detecting the accelerator position adjusted by pin 132；Determine the pinking sensing of tail gas igniting Device (not shown)；The measurement knot of engine manifold pressure (MAP) from the pressure sensor 122 for being connected to inlet manifold 44 Really；Carry out the engine position sensor of the Hall sensor 118 of the position of Autonomous test bent axle 40；From sensor 120 (for example, heat Wire type mass air flow sensor), the measurement result of air mass into engine；Throttle position measurement from sensor 58 As a result；The measurement result of the temperature difference on emission control system from temperature sensor 75,76,77；With from being connected to discharge The measurement result of air-fuel ratio difference on the emission control system of the lambda sensor (not shown) of the upstream and downstream of control device 70. Atmospheric pressure can also be detected and (not show sensor), to be handled by controller 12.In the preferred aspect of this specification, Bent axle often rotates once, and engine position sensor 118 produces the pulse at equal intervals of predetermined number, thus can determine that engine turns Fast (RPM).

Bent axle accelerates data also to be obtained by engine position sensor 118.As herein by detailed with reference to Fig. 3-4 institutes Carefully illustrate, under transient working condition and under steady state engine operating mode, bent axle accelerates data (can be based on passing through with exhaust heat release rise The exhaust temperature difference that temperature sensor 75,76,77 is assessed is determined) it is related, to indicate that the hydrocarbon at engine charge is accumulated.This can be wrapped Hydrocarbon is included in the accumulation (construction based on inlet manifold, as discussed in Fig. 2) selected at cylinder and/or compressor is being connected to The accumulation of the charger-air cooler in 162 downstreams near or on.Based on instruction, controller 12 can limit engine speed and negative Carry, to reduce further accumulation, so as to prevent engine performance decline in advance.For example, limitation can reduce steam-cylinder piston and its The performance degradation of its engine components.

Return to Fig. 1, in some embodiments, the electric motor/battery that engine may connect in motor vehicle driven by mixed power System.Motor vehicle driven by mixed power can have parallel construction, series configuration or its modification or combination.In addition, in some embodiments, Other engine constructions, such as Diesel engine can be applied.

During operation, each cylinder in engine 10 is usually subjected to four stroke cycles：The cycle include suction stroke, Compression travel, expansion stroke and instroke.In suction stroke, generally, exhaust valve 54 is closed and inlet valve 52 is opened.Air Combustion chamber 30 is introduced by inlet manifold 44, also, piston 36 is moved to cylinder foot, to increase the body in combustion chamber 30 Product.Piston 36 is close to cylinder foot and the position in its end of travel (for example, when the volume of combustion chamber 30 is maximum) is usual It is referred to by those skilled in the art as lower dead center (BDC).In compression travel, inlet valve 52 and exhaust valve 54 are closed.Piston 36 Towards cylinder cover movement, so as to the air in compression and combustion room 30.Piston 36 is in its end of travel and closest to cylinder cover Point (for example, when the volume of combustion chamber 30 is minimum) is generally referred to by those skilled in the art as top dead centre (TDC).Hereinafter by During referred to as spraying, fuel is introduced into combustion chamber.During hereinafter referred to as lighting a fire, the fuel of injection passes through Know igniter, such as spark plug 92 is ignited, cause burning.In expansion stroke, expanding gas promote piston 36 to be back to BDC.Bent axle 40 converts piston movement into the rotating torques of rotary shaft.Finally, in instroke, exhaust valve 54 is opened, with The air fuel mixture of burning is discharged to exhaust manifold 48, also, piston is back to TDC.Note, the above is only as example quilt Description, moreover, inlet valve and exhauxt valve opens and/or closure timings alterable, for example, overlapping to provide positive or negative valve opening Angle, lag IC Intake Valve Closes or various other examples.

Therefore, Fig. 1 systems provide engine system, and it is configured, so that by limiting engine speed and load, response refers to While the cylinder imbalance and engine exhaust heat release for showing hydrocarbon oxidation are raised, the hydrocarbon accumulation at engine charge is reduced. The controller of engine system can also improve engine temperature, to discharge or burn up the hydrocarbon of accumulation.Controller can be based on single Bent axle between engine cylinder (cylinder in such as different engine blocks) accelerates difference to determine that cylinder is uneven, wherein bent Axle accelerates to be evaluated under steady state engine operating mode and transition engine operating condition.The bent axle assessed under transition engine operating condition adds Speed difference is different to be evaluated on dynamically adapting window, and the dynamically adapting window is different from the window applied in a steady-state condition, its Middle dynamically adapting window is at least conditioned under transient working condition based on Mass Air Flow.Being vented heat release can be based in non-renewable shape The emission control assessed under condition (when delivery temperature is actively improved with the exhaust gas particulate filter of burn soot and regeneration Fig. 1) The exhaust temperature difference on device (such as Fig. 1 oxidation exhaust catalyst) is determined.By using exhaust heat release data and cylinder not Hydrocarbon at equilibrium criterion, engine charge, which is accumulated, can preferably be differentiated and be distinguished with the unbalanced other reasons of cylinder, and by It is appropriate to solve.

Referring now to Figure 2, display engine system (such as Fig. 1 engine system) --- including engine 201 --- Example embodiments 200, wherein paying special attention to the construction of motor intake manifold 202, the motor intake manifold 202 makes certain A little engine cylinders are easier to hydrocarbon accumulation.The new charge filtered by air purifier 212 is transported to by air intake duct 242 Engine 201.One or more sensors may connect to the downstream inlet road 242 of air purifier, such as MAP sensor and/ Or intake air temperature sensor, so that engine operating can be conditioned based on Income Air Status.Other MAP and intake air temperature sensor It may connect to inlet manifold.Engine 201 can be engine with supercharger, and it is configured to one or more turbocharger.Example Such as, engine 201 can be configured with first, low pressure turbocharger 260 and second, high pressure turbocharger 270.Low-pressure turbine Booster 260 includes the first compressor 262, and it is configured so that plenum.First compressor 262 can pass through the row of being connected to The rotation of first turbine 264 of gas passage 248 is driven.High pressure turbocharger 270 includes the second compressor 272, and it is connected In the downstream of the first compressor 262, and it is configured so that air inlet is further pressurized.Second compressor 272 can be by being connected to The rotation of second turbine 274 of the exhaust passage 248 of the upstream of one turbine 264 is driven.

Turbocharger actuator 276 --- being connected to turbocharger actuator arm 278 --- is connected to the first compression Between the compressor 272 of machine 262 and second.Turbocharger actuator 276 is configured, to realize using electric hydaulic driver or Electro-motor operates compressor.The air compressed by first (low pressure) compressor 262 is directed to second (high pressure) compressor 272, further to compress.The air inlet of compression is cooled by charger-air cooler 250, is then transferred to engine charge Manifold 202.

In the described implementation, engine 201 is configured to the inlet manifold 202 of branch, and it leads to two units Or two groups of cylinders 204,206.First group of cylinder 204 is located at the left side of inlet manifold 202, and it includes multiple cylinder 205a-d (at this Wen Zhong, four), and second group of cylinder 206 is located at the right side of inlet manifold 202, it includes multiple cylinder 207a-d (herein In, four).Air inlet can flow to inlet manifold 202 along air intake duct 242 from air throttle 252 (downstream of charger-air cooler 250) Breeches joint 203 (or Y-piece).The first outlet 208 of breeches joint 203 can pass air into first group of cylinder 204 (herein In, left inlet manifold), and the second outlet 210 of breeches joint 203 can pass air into second group of cylinder 206 (herein, right side Inlet manifold).The branch of breeches joint or the specific arrangement of outlet can be such：The longitudinal axis of each outlet is directed at each vapour Some cylinder of cylinder group.In the example of description, longitudinal axis alignment the first cylinder --- the cylinder of the first outlet 208 of breeches joint 203 205a, it is arranged away from end cylinder (herein, cylinder 205d), and the longitudinal axis pair of the second outlet 210 of breeches joint 203 Standard the second cylinder --- cylinder 207a, it is arranged away from end cylinder (herein, cylinder 207d).In particular, branch The arrangement of inlet manifold causes each outlet of cylinder 205a and 207a closest to breeches joint to be arranged.

Inlet manifold 202 may include one or more sensors, such as temperature sensor, pressure sensor and air-fuel ratio Sensor.For example, display MAP sensor 244 and intake air temperature (IAT) sensor 246 are connected to inlet manifold 202 and connect in Y types First 203.

Although motor intake manifold is commonly designed, so that air (and EGR) is uniformly distributed to single cylinder, enter The presence of uncontrolled hydrocarbon can cause unevenly to distribute in air-flow.Uncontrolled hydrocarbon can be from gas handling system, such as from biography The upstream of sensor 214, into the active particles filter Anywhere, reached up in gas extraction system.Uncontrolled hydrocarbon can be wrapped Include, for example, the hydrocarbon from fuel, cylinder oil and coolant.As an example, the mixture of multi fuel and oil is crossed Air intake duct 242 can be discharged to by crankcase bleed pipe 218 from engine crankcase.Excessive fuel and oil can enter bent axle Case, this be due to convey fuel to the high-pressure fuel system of injector fuel losses, by infrequently change oil oil enter, with And entered by the fuel of frequent regeneration exhaust gas particulate filter.As another example, oil can enter air inlet, and this is due in height Press the oil leakage in the sealing of turbocharger 270.As yet another example, coolant can be leaked to air inlet from cooler for recycled exhaust gas 230 In.Still other reason of hydrocarbon leakage may include cylinder fuel leakage path, the open type injector that blocks, the injection of cracking Device, the injector for having leakage, radiator leakage, cooler for recycled exhaust gas leakage etc..

During transition engine is operated, uncontrolled hydrocarbon (UHC) can be displaced by pouring in the unexpected inflation of engine cylinder Liquid bag（liquid pocket）, UHC sprayings are unevenly transported in cylinder with gas and liquid phase, this is due to used with droplet The relevant hydrodynamics of property.This uneven UHC distribution causes cylinder uneven.Fluid inertia can cause some cylinders, Cylinder 205a, 205d, 207a and 207d of all engine constructions as described, the more hydrocarbon of suction easier than other cylinders.Cause This, impacted cylinder according to the design and construction of breeches joint and the inlet manifold of engine system largely not Together.

Specifically, in the engine construction of description, the entrance of inlet manifold 202 is curved into from right to left to be come (see solar term The bending of air intake duct near door 252).As a result, on the left of inlet manifold (that is, first group cylinder 204) obtain substantial amount not by The hydrocarbon fluid of control (as shown in arrow 290).Because inlet manifold is straightened then along cylinder cover, so most of hydrocarbon fluid Accumulation then will occur in manifold end, so that cylinder 205d will finally give most of hydrocarbon fluid.In addition, cylinder 205a also will Obtain a part of hydrocarbon fluid.Specifically, transformation/bending of inlet manifold will make fluid deflector, but due to being produced in the position Turbulent flow, also there will be some flow of hydrocarbon and is inhaled into cylinder 205a.

Because uncontrolled hydrocarbon is in liquid-vapour phase, also, fuel particle is heavier than air, so, they are being inhaled into Tend to unevenly be distributed when in engine cylinder.With reference to Fig. 2 exemplary engine embodiment, appointing for engine is inhaled into Meaning waste（debris）, the uncontrolled hydrocarbon such as from fuel and oil, will tend to stop and accumulate in cylinder 205a and 207a.In addition, accumulation may be present in cylinder 205d.After uncontrolled hydrocarbon oxidation at exhaust catalyst, the accumulation can be led Cause substantive casing top half uneven and heat release rise.

In particular, in compression ignition engine (such as Diesel engine), the lean burn of uneven positioning causes hydrocarbon to burn, Soot and heat are produced by exothermic reaction.Similarly, in some cylinders, uneven hydrocarbon distribution causes excessive bent axle to add Speed.For example, hydrocarbon can be lighted in a combustion chamber, and cause racing of the engine and situation of overrunning.In an example, cylinder balance can Refer to fuel injector reinforcing applied to specific cylinder time adjustment so that the specific cylinder in terms of its ability as other start Machine cylinder is equally showed, to produce the acceleration of peak value bent axle.Accordingly, it is determined that producing more than expected or less than the acceleration of expected bent axle Cylinder performance cylinder is uneven.As elaborated herein, cylinder imbalance can be accelerated difference and is determined based on bent axle. For example, accelerating by the peak value of relatively more each cylinder and (that is, realizing that the bent axle of peak cylinder pressure accelerates) and model threshold, it can examine Survey cylinder uneven.With exhaust heat release rise simultaneously detection these cylinders imbalance reflection due at engine charge not by Hydrocarbon is aoxidized caused by the hydrocarbon accumulation of control.Therefore, if making its uncontrolled, accumulation can continue to gather and finally overflow into In other cylinders, substantial engine performance is caused to fail.

In an example, if relatively large waste is accumulated at cylinder 205a (in the left side of engine charge) place, vapour Cylinder imbalance relevant issues can take place mostly in second group of cylinder on the right side of inlet manifold.As another example, if relatively large Waste is accumulated at cylinder 207a (on the right side of engine charge) place, then the uneven relevant issues of cylinder can take place mostly in air inlet First group of cylinder on the left of manifold.

Uncontrolled hydrocarbon can be also accumulated in charger-air cooler 252.Specifically, with various oil and fuel leakage It is drained into crankcase, the increase of crankcase fluid volume.As volume is increased above bent axle level, the bent axle blending of rotation is excessive Fuel and oil and air inlet, formed foaming oil mixture.Then, crankcase bleed pipe 218 can transport foam oil mixture to whirlpool Take turns the air intake duct 242 of the upstream of turbocharger compressor 262 and 272.Revealed in coolant from cooler for recycled exhaust gas and oily from turbocharger In the case of sealing leakage, uncontrolled hydrocarbon can be directly entered air intake duct from all parts.Oil/fuel mixture passes through turbine The compression of booster and cause uncontrolled hydrocarbon vapour mixture in the bag of various gas handling systems through charge cooler, especially Ground, in charger-air cooler 252, condensation.During transition engine is operated, such as during accelerator pedal is stepped on, fill Gas can displace the liquid bag of uncontrolled hydrocarbon to pouring in suddenly for cylinder, and being sprayed to for hydrocarbon is mutually unevenly transported with vapour-liquid In cylinder, this is largely due to the hydrodynamics relevant with droplet inertia.As described above, uneven distribution meeting Cause cylinder uneven.Partially combusted hydrocarbon into gas extraction system can trigger uncontrolled oxidation rate, cause exhaust to be put Heat rise (for example, in exhaust oxidation catalyst, up to 65 degrees Celsius per second of temperature rise).

Return to Fig. 2, the combustion product of first group of cylinder 204 can be released to first exhaust manifold 212, and second group of cylinder 206 combustion product can be released to second exhaust manifold 214.At least partly exhaust can be used for revolving turbocharger turbine Turn, be then released in air.For example, exhaust through passage 282,284 can be conducted through second from exhaust manifold 212,214 Turbine 274.

In addition, in the case where requiring the situation of exhaust gas recirculatioon (such as when requiring engine dilution), at least partly exhaust can The engine charge for returning to the downstream of air throttle 252 is diverted by EGR channel 231.In the described implementation, EGR is shown Passage 231 turns to exhaust from second exhaust manifold 214, although it should be understood that in alternate embodiments, exhaust can be from first row The exhaust manifold 212 and 214 of gas manifold 212 and/or two is diverted.EGR channel may include emission control system, such as oxidation catalysis Agent 232, the exhaust of engine cylinder is recycled to for handling.One or more coolers for recycled exhaust gas, such as first (level) EGR Cooler 236 and second (vertical) cooler for recycled exhaust gas 238 may include in EGR channel 231, for cold before cylinder is delivered to But it is vented, so as to provide cooling EGR benefit to engine.By adjusting the unlatching of EGR damper 247, engine is recycled to The capacity of air inlet can be conditioned.One or more sensors, such as temperature sensor, pressure sensor and/or sky-right ratio are passed Sensor, may connect to egr system, with amount, timing, composition and the temperature of the exhaust for controlling to be diverted to engine charge.For example, First EGR entrance sensor 230 (temperature or sky-so than sensor) is attached to the upstream of the entrance of EGR channel 231, and the Two EGR outlet sensors 240 (temperature or sky-so than sensor) are attached to the upstream of the outlet of EGR channel 231, such as EGR gas 240 upstreams of door.As another example, back pressure transducer 245 may include in EGR channel 231.

As herein by with reference to Fig. 3 model and Fig. 4-5 program elaborated, engine controller can by with Put, the unbalanced detection of cylinder determines hydrocarbon oxidation during with based on exhaust heat release rise and based on exhaust heat release rise, and controller can Infer the hydrocarbon accumulation at engine charge.Therefore, controller can perform one or more operations, including limitation engine speed and Load, to reduce the release of further accumulation and hydrocarbon to air inlet.By doing so it is possible, initial cylinder imbalance can be solved, Also, because the uneven and potential engine performance decline of further cylinder can be lowered caused by accumulation hydrocarbon.In addition, Due to exhaust system component caused by exhaust heat release rise, the performance degradation of such as oxidation catalyst and particulate filter also may be used To be lowered.

Referring now to Figure 3, the schematic diagram (or block diagram) of its display methods 300, method 300 is used to detect engine charge The hydrocarbon at place is sucked and quickly reacted with inhalation (inhalatio), is failed with mitigating serious engine performance.Therefore, Fig. 3 methods are to Fig. 4-5 Program in apply algorithm block diagram description.

Method 300 includes steady state condition monitor 302, for persistently detecting and assessing engine steady operation.In addition, mistake Cross state monitor 304 to be provided, for persistently detecting and assessing transition engine operating condition.Transition state monitor 304 includes Dynamic lag is compensated（dynamic lag compensation）With the window of dynamic adjustment size（sizing window）, its In, transient working condition is evaluated.Window (for example, window start and end points for monitoring) is at least based on the amount for stepping on accelerator pedal (for example, movable based on the accelerator pedal during stepping on accelerator pedal).Dynamic lag compensation allows and row uneven to cylinder Monitoring is weighted while gas heat release, to accelerate the detection sucked to hydrocarbon.Dynamically adapting window is such window：Wherein, wink State cylinder unbalanced data is measured, also, can be dynamically adjusted based on transition engine operating condition.For example, working as transient working condition It is that window based on Mass Air Flow, the rate of change of Mass Air Flow and/or can step on accelerator and step on when stepping on accelerator pedal Plate amount (as during accelerator pedal is stepped on as accelerator pedal activity determined by).

Various noise filtering technologies are used for analysis bent axle and accelerate data, so as to the factor of abating the noise, such as misfire, tide Wet, fuel mass.These filtering techniques may include, for example, noise Solve Problem, noise filtering technology, such as Key dithering algorithm, Deviation accumulation calculating device etc..The function of Key dithering algorithm is to be accelerated to set the time of failure according to error size.When cylinder is uneven When weighing apparatus and/or heat release are high, then fault flag is set quickly.In addition, Key dithering algorithm is cut off（clip）The maximum of calculator Value, and calculator is zeroed when being unsatisfactory for and entering situation.This allows setting the prior fault of fault flag ripe enough.With this The mode of kind is there is provided the uneven algorithm of enhanced cylinder, and it in idling mode situation in addition to operating, also in transition engine work Operated under condition.

Belong to the data of each transition state situation --- as determined by transition state monitor 304, and belong to every The data of one steady-state conditions --- as determined by stationary monitor device 302, can abreast it be transported to based on the unexpected of model Heat release process of measurement block 306 and the cylinder disequilibrium survey program block 308 based on model.Cylinder disequilibrium survey based on model The model applied in program block 308 can be based on engine running parameter, such as engine speed, the fuel of injection, quality air Flow (MAF) and entering air temperature (IAT).These parameters are at least based on, model can determine that the amount that piston accelerates.

The uncontrolled hydrocarbon of stable state (UHC) of weighting is abreast transported to from the respective output of program block 306 and 308 Monitor 312 and the transient state UHC monitors 310 of weighting., can driscrimination error state based on the comparison between monitor 310,312 314.In particular, in a steady-state condition, the cylinder that response passes through the heat release detected of model 306 and detected by model 308 is uneven Weighing apparatus, the stable state UHC monitors 312 of weighting can determine that at hydrocarbon suction and engine exhaust under steady-state conditions at engine charge Hydrocarbon is aoxidized.Similarly, under transient working condition, heat release that response is detected by model 306 and the cylinder that is detected by model 308 are not Balance, the transient state UHC monitors 310 of weighting can determine that at hydrocarbon suction and engine exhaust under transient working condition at engine charge Hydrocarbon oxidation.In addition, the output by comparing monitor 310 and 312, it may be determined that error state 314 and settable mark.Pass through Using and compare the data received under transient working condition and steady-state conditions, even if less cylinder is uneven and exhaust heat release Can preferably it be detected.In addition, cylinder unbalanced data can be made associated with the exhaust heat release data with high confidence, from And improve the detection sucked to hydrocarbon.By improving the accuracy and intensity of inspection policies, hydrocarbon suction can be in hydrocarbon in engine charge Place is detected and solved before building up to the level for causing substantial engine components performance degradation.

The detection to error state 314 is responded, restoration strategy is can perform（healing strategy）316, it is to be based on Multiple affair travels cycle monitoring more.Many traveling cycle monitorings, which are included in, starts mitigation FMEM operations, before such as reduction moment of torsion, The ability of error state 314 is monitored in multiple driving cycles.Restoration after a failure can be also calibrated, with multiple driving cycles by Gradually restore, can soon to set failure when error state is too frequent.Restoration strategy fails including various engine performance Slow down step and fault model and effect management (FMEM) operation 318.The operation performed as the part of restoration strategy includes Limit engine speed and load.In an example, by reducing to all engine cylinders --- including detecting injustice Weigh (for example, racing of the engine) engine cylinder and not yet cause the unbalanced other cylinders of cylinder --- fuel spray Penetrate, limitation engine speed and load.Engine speed reduction reduces crankcase foaming and increase engine is filled to crankcase The tolerance of overfill.In addition, limitation engine speed and load allow peak cylinder pressure to reduce.In other instances, start Machine rotating speed and load can be opened by reducing air throttle, reduced amount, increase EGR amount of engine booster etc. and further limited System.

Other restoration strategy step includes increase engine temperature, to discharge the hydrocarbon of some accumulation.In particular, accumulation The in check burning of hydrocarbon allows cylinder infringement to be reduced and/or be tolerated.Still other restoration strategy step includes warning car Driver, so that vehicle can be delivered to service center by driver, further to assess.It is available to be shown in dashboard displays On message in groups or by illuminate malfunction indicator lamp (or spanner lamp) alert vehicle driver.Further, various examine can be set Division of history into periods code, it can be retrieved by the maintenance personal of service center, and for preferably reviewing hydrocarbon suction event.

Referring now to Figure 4, method 400 describes program, it is under stable state and transition engine operating condition, continuous assessment and monitoring Bent axle accelerates data and exhaust temperature data, to reliably detect and indicate the hydrocarbon suction at engine charge.It can respond and refer to Show that the alleviation step of the reduction engine performance decline of execution is explained fully in Fig. 5 program.Therefore, Fig. 4-5 program should With the algorithm introduced before in Fig. 3.

402, method includes assessing and/or measurement engine operating condition.These include, for example, engine speed and load, Driver torque request, delivery temperature, exhaust catalyst temperature, boost pressure level, environmental aspect (environment temperature, pressure, humidity Deng), manifold pressure, manifold air flow etc..

404, it may be determined that engine transition operating mode whether there is.In an example, if the change of Mass Air Flow Change speed be higher than threshold rates, it may be determined that engine transition operating mode, such as during accelerator pedal is stepped on or unclamp step on accelerator During pedal.If transient working condition not confirmed, 424, program includes determining that engine steady state situation whether there is.One In individual example, if the speed change of Mass Air Flow is less than threshold rates, it may be determined that engine steady state situation.In another reality In example, if engine is in engine idling, engine steady state situation can determine that.

After transient working condition is confirmed, the bent axle between 406, single engine cylinder accelerates difference to be determined.Class As, after steady-state conditions are confirmed, the bent axle between 426, single engine cylinder accelerates difference to be determined.Especially Ground, when engine is in steady-state conditions, bent axle accelerates difference to be evaluated in first window, and when engine was in ferryman During condition, it is evaluated in second, different window.Therefore, under transition engine operating condition, at least based on transition engine operating condition Under Mass Air Flow or Mass Air Flow rate of change, the second window may be adjusted dynamically.By contrast, first Window can be based on stable engine speed and load.Except limit stable state and transient working condition certain window entrance situation it Outside, the core of the entrance situation based on car speed, environment temperature, coolant temperature, PTO states, error originated from input state etc. is set Put（core set）Available for the second window under the first window and transient working condition determined under steady-state conditions.For example, according to vapour Cylinder imbalance degree and heat release size windows can be wider or narrower.For example, for the error state of phase same level, first window can Less than the second window.

The bent axle that various noise filtering technologies and algorithm can be used for filtering in each window accelerates data.For example, in stable state Under situation, bent axle accelerates difference can be by Key dithering between the cylinder in first window.Similarly, under transient working condition, the second window Bent axle accelerates difference can be by Key dithering between middle cylinder.

408, data (406) are accelerated based on the bent axle assessed under transient working condition, it may be determined that cylinder is uneven.It is similar Ground, 428, data is accelerated based on the bent axle assessed in a steady-state condition (426), it may be determined that cylinder is uneven.In a reality In example, engine includes different units, wherein with groups of cylinder, such as the first unit and tool with the first cylinder group There is the second unit of the second cylinder group.Wherein, based between the respective single engine cylinder of first and second groups of cylinders Bent axle accelerates difference, determines that cylinder is uneven, assessing bent axle respectively under steady state engine operating mode and transition engine operating condition adds Speed.

In an example, as fuel injector reinforcing cylinder makes the cylinder in terms of ability as other engine cylinders Equally show to produce the time adjustment needed for peak value bent axle accelerates, cylinder balance can be evaluated.Therefore, if cylinder relative to Other cylinders (other cylinders in such as identical group) produce too much or it is very few produce bent axle acceleration, then can determine that cylinder not Balance.If not determining that cylinder is uneven 408 or 428, program can terminate.

Accelerate difference if based on the bent axle in the second crankangle window, determine that cylinder is uneven 408, then 416, control The settable mark of device processed or diagnostic code, to indicate that the hydrocarbon under transient working condition at engine charge is accumulated.Specifically, mark can Indicate that the hydrocarbon accumulation under transient working condition at engine charge alreadys exceed the boundary of permission --- as determined by by model. Similarly, accelerate difference if based on the bent axle in the first crankangle window, determine that cylinder is uneven 428, then 436, control The settable mark of device processed or diagnostic code, to indicate that the hydrocarbon at engine charge in a steady-state condition is accumulated.Specifically, mark can Indicate that the accumulation of the hydrocarbon at engine charge in a steady-state condition alreadys exceed the boundary of permission --- as determined by by model. Therefore, for indicating that the mark or diagnostic code of hydrocarbon accumulation may differ from being used to indicate hydrocarbon in a steady-state condition under transient working condition The mark or diagnostic code of accumulation.In a steady-state condition, the value --- assessing hydrocarbon accumulation 436 for it --- of model can basis Engine speed and environment temperature are determined.

It is parallel with step 406 and 408,410, it may be determined that whether particulate filter is reproduced.Similarly, with step 426 It is parallel with 428,430, it may be determined that whether particulate filter is reproduced.Therefore, engine exhaust may include one or more rows Put control device, such as particulate filter and the exhaust oxidation catalyst for being arranged in particulate filter upstream.In particulate filter Under the situation being reproduced, the delivery temperature of emission control system can be improved actively, to burn soot and to be accumulated in particulate Particle matter in filter.Therefore, for cause the heat release rise undergone due to effective filter regeneration with because hydrocarbon is sucked Caused by heat release rise make a distinction, program only proceeds confirming to exist after non-renewable situation is present.

In 412 and 432, exhaust heat release is assessed respectively under transient working condition and steady-state conditions.In a steady-state condition, exhaust is put Heat can be evaluated during first window, and under transient working condition, can be evaluated during the second window.Heat release can be based on exhaust The exhaust temperature difference on oxidation catalyst.Therefore, 412, when particulate filter is not reproduced, under engine transition operating mode, The exhaust temperature difference in exhaust oxidation catalyst is evaluated in a second window.Similarly, 432, when particulate filter is not by again When raw, under engine steady state situation, the exhaust temperature difference in exhaust oxidation catalyst is evaluated in first window.Next, In 414 and 434, it may be determined whether there is heat release rise.For example, it may be determined that the exhaust temperature difference in the exhaust oxidation catalyst assessed Whether threshold difference is higher than.

Therefore, if heat release unconfirmed is raised, program can terminate.By contrast, if in a steady-state condition first Heat release rise is determined in window or determines that heat release is raised in a second window under transient working condition, then in 416 and 436, controller Appropriate mark or diagnostic code is set, to indicate that hydrocarbon accumulation alreadys exceed the boundary of permission.

Although above-mentioned steps are described in detail under transient working condition or steady-state conditions the vapour in the crankangle window based on restriction Cylinder imbalance or heat release raise the hydrocarbon suction differentiated at engine charge, but based on cylinder imbalance in restriction window and can also put The instruction for performing hydrocarbon suction occurs while heat rise is respective.In particular, cylinder velocity variations can such as be fired due to various factors Material ejector change, cylinder charging change, misfire and hydrocarbon suck (such as fuel and/or oil) and are caused.Similarly, exhaust is put Heat rise can be caused due to various factors.Herein, inventor has recognised that by making cylinder uneven and exhaust Heat release rise is associated, because cylinder imbalance can preferably be different from and be inhaled by hydrocarbon caused by fuel injector change or misfire Cylinder is uneven caused by entering, so as to allow to take appropriate alleviation step.This include hydrocarbon suction can be made by earlier and/or More accurately detect.

For example, after 408 determine that cylinder is uneven under transient working condition, program is optionally carried out to 414, to determine Whether heat release rise occurs simultaneously in identical window.If it is, 416, response cylinder is uneven and heat release rise is each From while occur, it may be determined that hydrocarbon is sucked, also, the settable mark of controller, to indicate the engine charge under transient working condition The hydrocarbon accumulation at place alreadys exceed the boundary of permission --- as determined by by model.As another example, ferryman is being crossed 414 Determined under condition after heat release rise, whether program is optionally carried out to 408, to determine cylinder imbalance in identical window Occur simultaneously.If it is, in 416, the settable mark of controller, to indicate that the hydrocarbon under transient working condition at engine charge is inhaled Enter.Herein it should be understood that compared with the setting of response cylinder imbalance or the elevated mark of heat release, indicating the mark of hydrocarbon suction Set while being raised in response to cylinder imbalance and heat release and occur and relatively early generation.

In an identical manner, after 428 determine that cylinder is uneven in a steady-state condition, program optionally carry out to 434, to determine whether heat release rise occurs in identical window simultaneously.If it is, 436, response cylinder it is uneven and Heat release rise occurs while respective, it may be determined that hydrocarbon is sucked, also, the settable mark of controller, to indicate in a steady-state condition Hydrocarbon accumulation at engine charge alreadys exceed the boundary of permission --- as determined by by model.As another example, After 434 determine heat release rise in a steady-state condition, program is optionally carried out to 428, with determine cylinder it is uneven whether Occur simultaneously in identical window.If it is, in 436, the settable mark of controller, to indicate engine in a steady-state condition Hydrocarbon suction at air inlet.Herein it should be understood that compared with the setting of response cylinder imbalance or the elevated mark of heat release, indicating hydrocarbon The setting of the mark of suction can occur and relatively early occur while and heat release rise uneven in response to cylinder.

It should be understood that under the situation that both of which exceedes, during it is determined that hydrocarbon is sucked, to cylinder unbalanced data and exhaust The weighting of heat release data can be detected in transient working condition or in a steady-state condition and different based on cylinder imbalance.For example, The instruction of each in difference and the exhaust temperature difference is accelerated to may include based on bent axle poor with the weighting bent axle acceleration of the first weight factor The weight factor weighting exhaust temperature difference different and with second, different, the first and second weight factors at least accelerate difference based on bent axle It is to be evaluated under transient working condition or in a steady-state condition.

After indicating that the hydrocarbon at engine charge is accumulated, response indicates that the cylinder of hydrocarbon oxidation is uneven and/or engine is arranged Gas heat release is raised, and can perform one or more alleviation steps 416 and 436.Fig. 5 is such as explained fully in, these may include, example Such as, limitation engine speed and load, are accumulated with reducing the hydrocarbon at engine charge.

Referring now to Figure 5, method 500 describes program, it responds the hydrocarbon under transient working condition or steady state engine operating mode and sucked Instruction, perform various alleviation steps.Hydrocarbon suction can be based on being vented heat release liter under transient working condition or under steady state engine operating mode Bent axle accelerates difference (or cylinder is uneven) and is determined between each cylinder undergone when high.

502, program includes rise engine temperature, to discharge the hydrocarbon accumulated at engine charge.Herein, inhale The in check burning of the hydrocarbon entered is so that the hydrocarbon load at engine charge is reduced, also, further cylinder imbalance also subtracts It is few.

504, program includes limitation engine speed and load.Specifically, limitation includes limitation to all engine vapour The fuel injection of cylinder.In an example, in the case where engine includes the first and second cylinders, based on exhaust catalyst It is vented each bent axle when the temperature difference is higher than threshold value between the first cylinder and the second cylinder and accelerates difference, can be indicated in the first cylinder Hydrocarbon is accumulated.In response to it, it can be limited to the respective fuel injection of the first and second cylinders, to reduce engine speed and bear Carry.Herein, by reducing engine speed, the engine crankcase foaming that hydrocarbon can be caused to suck is reduced.

The degree of limitation is based on bent axle and accelerates difference to be under transition engine operating condition or under steady state engine operating mode It is authenticated.For example, limitation may include when engine is in steady-state conditions, with first, relatively large limit to all engine vapour The fuel injection (for example, each in examples detailed above in the first and second cylinders) of cylinder, and when engine is in transient working condition When, the fuel injection to all engine cylinders is limited (for example, the first and second cylinder in examples detailed above with second, small amount In each).In addition, the amount of limitation can be based on the unbalanced degree of cylinder and the exhaust elevated elevated-levels of heat release.

506, program also includes setting diagnostic code and illuminates trouble light, to indicate that the hydrocarbon at engine charge is accumulated. In an example, the instruction sucked based on hydrocarbon is to be received under transient working condition or in a steady-state condition, and difference can be set Diagnostic code.Trouble light can be, for example, spanner lamp.In addition, lamp can be shown on instrument board screen (or panel) into Group message, to alert vehicle driver.Lamp and message can be used for warning vehicle driver that vehicle is delivered into service center, to enter One step is repaired.Vehicle is set to be repaired as early as possible by alerting vehicle driver, reduction is due to first stage motor caused by hydrocarbon suction Can decline.In addition, it is possible to decrease because cylinder is uneven and the caused secondary engine performance decline of heat release rise.

In an example, under the first engine steady state situation, based on the assessment in first window in a steady-state condition Cylinder between bent axle accelerate difference and exhaust heat release rise, controller may indicate that at engine charge hydrocarbon (HC) accumulation. Under engine with two transient working condition, difference and exhaust are accelerated based on bent axle between the cylinder assessed in a second window under transient working condition Heat release is raised, and controller may indicate that the HC accumulation at engine charge.Under the first and second situations, controller can be responded Indicate fuel injection of the limitation to all engine cylinders.

Herein, in a steady-state condition, first window is based on engine speed and moment of torsion (such as stable engine Rotating speed and moment of torsion), and under transient working condition, the second window is to be based on stepping on accelerator pedal.For example, first window is than the second window Mouth is wide.Controller can also perform extensive noise filtering in each window.For example, controller can go down in the first steady-state conditions Bent axle accelerates difference between shaking the cylinder in first window, and under the second transient working condition, the cylinder in the window of Key dithering second Between bent axle accelerate difference.

Response indicates that limitation may include to the fuel injection of all engine cylinders：If it is indicated that in engine steady state situation It is lower to be received, fuel injection is limited with the first weight factor, and if it is indicated that received under engine transition operating mode, with second Weight factor limits fuel injection, and the first weight factor is higher than the second weight factor.For example, controller can be in the first steady-state conditions Under, with first, it is relatively large limit under the fuel injection and the second transient working condition of all engine cylinders, with second, small amount Limit the fuel injection to all engine cylinders.In addition, the amount of limitation can be based on the unbalanced degree of cylinder and exhaust heat release Elevated elevated-levels.

As another example, controller can be during first steps on accelerator pedal, based on the vapour assessed in first window Bent axle accelerates difference and exhaust heat release between cylinder, indicates the HC accumulation at engine charge, and steps on the accelerator pedal phase second Between, difference and exhaust heat release are accelerated based on bent axle between the cylinder assessed in second, different window, indicated in engine charge The HC accumulation at place.Then, during first and second step on accelerator pedal, Key dithering calculator can be increased.When Key dithering is calculated When device is higher than model threshold, then response is indicated, can limit the fuel injection to all engine cylinders.

Herein, starting for first window can be based on empty by the quality of engine during first steps on accelerator pedal The rate of change of throughput, and the starting of the second window is based on empty by the quality of engine during second steps on accelerator pedal The rate of change of throughput.The duration that two windows are opened can be the function of Mass Air Flow.By contrast, fuel Injection can be independent of Mass Air Flow rate of change, be only used for determine window of opportunity, in the window of opportunity, need Occur both uneven monitorings of exhaust heat release with DOC of cylinder.

By this way, based on data received in a steady-state condition or under transient working condition, bent axle accelerates data It can be processed in different windows.By using the data handled under transient working condition and idling/steady-state conditions, sucked by hydrocarbon Caused cylinder imbalance can be detected more reliably.Similarly, response hydrocarbon suction instruction limitation can based on instruction be Differently adjusted under steady-state conditions or under transient working condition by reception, preferably to mitigate hydrocarbon accumulation.

In an example, the hydrocarbon leakage from each introduces a collection can be drained into engine crankcase.The connection of engine Bar can stir crankcase oils, and the crankcase oils cause to foam in crankcase when mixing with hydrocarbon.Hydrocarbon foam can be by connecting bent axle Case and the crankcase bleed pipe of air inlet are moved to engine aspirating system.In addition, the hydrocarbon leakage from each introduces a collection can be arranged directly Enter to engine charge.As hydrocarbon is accumulated in engine charge, small hydrocarbon pond is formed（pool）.The unexpected of air is poured in --- As being undergone during stepping on accelerator pedal, hydrocarbon pond can be displaced, and hydrocarbon is moved in engine cylinder, wherein due to air inlet The construction of manifold, the other cylinders of some cylinder ratios suck more hydrocarbon.Because hydrocarbon is sucked in engine cylinder, uncontrolled combustion Burning can occur in a combustion chamber, to cause cylinder uneven.Meanwhile, the hydrocarbon that can be not involved in combustor inner cylinder is transported to exhaust system System, in the gas extraction system, unburned hydrocarbon is oxidized (in particular, at exhaust DOC).This causes uncontrolled on DOC It is vented heat release.Therefore, by monitoring heat release rise on exhaust DOC and monitoring the unbalanced cylinder acceleration data of cylinder simultaneously, It accurately can diagnose and solve hydrocarbon suction.

In an example, controller can confirm one group general " core enters situation ", i.e. such entrance situation：Its It must be satisfied, to realize to being vented heat release and the unbalanced monitoring of cylinder to be initiated on diesel oxidation catalyst.These enter Entering situation includes, for example, the environment temperature in window, the coolant temperature higher than threshold value, the car speed higher than threshold value or by The PTO situations of instruction.In addition, the error state of above-mentioned input can be instructed to.

Next, controller can confirm the entrance situation of heat release detection, i.e. such situation：It must be satisfied, with reality Now to the monitoring of heat release.These include, for example, (wherein described threshold value is the letter of environment temperature higher than the DOC inlet temperature of threshold value Number), the dpf regeneration situation that is not in regeneration, fully warm exhaust DOC, the exhaust DOC outlet temperature higher than threshold value, referred to The thermally-stabilised gas extraction system shown (after dpf regeneration or after quick parking-starting).At the same time, controller can confirm that cylinder is uneven Weigh the entrance situation detected.This may include to confirm that DPF does not regenerate.The premise detected for stable state may include to confirm that engine turns Speed is in window, motor torque is in window and engine speed and moment of torsion are stable.Before transition state detection Carrying may include, for example, the rate of change based on Mass Air Flow, determines the beginning of detection window, and based on quality air stream Dynamic speed, determines the end of detection window.

After all entrance premises and situation are satisfied, the cylinder imbalance occurred in each window and heat release are responded Rise --- as limited for stable state and transient working condition, controller can determine that hydrocarbon in engine charge and/or crankcase Accumulation and needs take alleviation step to reduce further accumulation.

By this way, the uneven correlation between exhaust heat release rise of cylinder can be used for differentiating that hydrocarbon enters along engine The accumulation of gas system.Assessed by using the signal transacting and extensive algorithm of essence in stable state and in transition engine work The cylinder unbalanced data collected under condition, can be reduced due to misfire or because hydrocarbon undergoes in the accumulation of optional engine location Noise factor, also, can more accurately diagnose the accumulation of the hydrocarbon at engine charge.By controllably to limit engine speed With load response accumulation, substantive engine performance decline can be suppressed.

As that will be understood by one of ordinary skill in the art, program described herein can represent arbitrary number processing strategy One or more of, the tactful event-driven of processing, interruption driving, multitask, multithreading etc..Therefore, it is shown Each step or function can be performed in shown program, parallel to perform, or are omitted in some cases.Similarly, no Necessarily require that processing sequence reaches target as described herein, feature and advantage, and be to provide conveniently to illustrate and describe.Although not yet There is clearly example, but one of ordinary skill in the art will recognize that, the step of one or more examples or function can be weighed Multiple to perform, this depends on applied specific strategy.

Terminate specification now.Those skilled in the art is by reading this specification, it will expects many changes and repaiies The spirit and scope changed without departing from this specification.For example, the I3 operated with natural gas, gasoline, diesel oil or optional fuel placement, I4, I5, V6, V8, V10 and V12 engine can apply present specification, to obtain benefit.

Claims (10)

1. for the method for engine, including：

Response indicates cylinder imbalance and engine exhaust heat release rise, limitation engine speed and the load of hydrocarbon oxidation, to subtract Hydrocarbon accumulation at few engine charge.

2. the method described in claim 1, further comprises：Air inlet is set to flow to breeches joint from air throttle, then from the Y types The first outlet of joint flow to first group of cylinder and the second outlet from the breeches joint flow to second group of cylinder, and the Y types connect The first cylinder that the longitudinal axis alignment of the first outlet of head is arranged away from described first group of end cylinder, the breeches joint The second outlet the longitudinal axis alignment away from described second group end cylinder arrange the second cylinder.

3. the method described in claim 2, wherein cylinder imbalance is respective based on described first group and second group of cylinder Bent axle between single engine cylinder accelerates difference, and the bent axle accelerates in steady state engine operating mode and transition engine work It is evaluated under condition.

4. the method described in claim 3, wherein, it is described that the bent axle assessed under transition engine operating condition accelerates difference to be included in The bent axle assessed under transition engine operating condition on dynamically adapting window accelerates difference, and the dynamically adapting window is at least based on Mass Air Flow under the transition engine operating condition is conditioned.

5. the method described in claim 3, wherein the engine exhaust includes oxidation catalyst and particulate filter, also, Wherein described exhaust heat release is based on the oxidation exhaust assessed when particulate filter is not reproduced under engine steady state situation The exhaust temperature difference of catalyst both sides.

6. the method described in claim 2, wherein, limitation engine speed and load include limitation to all engine cylinders Fuel injection.

7. the method described in claim 2, wherein, the degree of limitation is to accelerate difference to be in transition engine operating condition based on bent axle It is authenticated down or under steady state engine operating mode.

8. the method described in claim 2, further comprises：Diagnostic code is set and trouble light is illuminated, to indicate described start Hydrocarbon accumulation at machine air inlet.

9. the method described in claim 2, further comprises：Engine temperature is raised, to discharge at the engine charge The hydrocarbon of accumulation.

10. for the method for engine, including：

Each bent axle when the exhaust temperature difference based on exhaust catalyst group is higher than threshold value between the first cylinder and the second cylinder accelerates Difference, indicates the hydrocarbon accumulation in the first cylinder；With

In response to it, limit to the first and second cylinders fuel injection of each.